1. Field of the Invention
The present invention relates to apparatuses and methods that assist in the movement of a wheelbarrow, particularly for heavy loads and/or on a hill or incline.
2. Related Art
The basic concept of a wheelbarrow to carry loads over a distance has been in existence in various forms since at least the Middle Ages. The design of many classic or standard wheelbarrows in use today typically include rear supports, two arms or handles, at least one wheel, and a tray for holding the load. A typical wheelbarrow may also include various support structures and wheel-mounting pieces, such as an axle, etc., depending on the particular design and construction. The tray (also referred to as a bed or pan) is typically open on top and has a bottom wall and upward-extending front, back and/or side walls that contain and hold the load and keep it from spilling when the wheelbarrow is an upright position. The term “upright” in reference to a wheelbarrow means having the large opening on top of the tray facing generally upward away from the ground. The two arms or handles typically extend rearward from the back of the wheelbarrow for grabbing, lifting, turning, maneuvering, etc., by the hands of a user. The rear supports typically extend downward from the tray closer to the back of the wheelbarrow and may be attached, fastened, etc., to the tray itself or to the arms/handles.
At least one wheel is typically located near the front of the wheelbarrow and is held in place by attachment, connection, etc., of its wheel axle to the wheelbarrow. However, the wheel axle may be freely or fixedly connected to the wheelbarrow in a number of different ways. For example, the two rearwardly extending arms or handles may also have forward portions that extend out in a forward direction in front of the wheelbarrow tray. With these wheelbarrow designs, it is common for a single front wheel to be positioned between, and connected to, the forward portions of the arms or handles in front of the wheelbarrow tray. The front wheel axle may be held in place by wheel mounts fastened to the arms/handles or by insertion of the wheel axle through holes in the arms/handles themselves with additional wheel-mounting hardware. There may also be additional wheel supports that bridge from the tray to the forward portions of the arms/handles to provide additional strength. A cross support(s) may also be provided between corresponding portions of the two rear supports. Many other wheelbarrow designs exist as well. For example, instead of mounting the wheel axle to the arms or handles, the front wheel may be held in place by separate wheel-mounting structures that extend down from the wheelbarrow tray. As another example, a frame, which may include the rear supports, the arms/handles, and/or forward wheel-mounting structures, may be attached, connected, etc., to the wheelbarrow tray. With each of these classic designs, additional front support(s) may also be present that bridge between the tray and the arms/handles or frame near the front wheel(s).
In a resting state, the front wheel(s) and rear supports of a typical wheelbarrow will rest on the ground and share in supporting the combined weight of the wheelbarrow and its load (if any). The bottom portions of the downwardly extending rear supports, or one or more wheels, feet, etc., at the bottom of the rear supports, will contact the ground directly. When the back of a wheelbarrow is lifted off the ground by a user lifting up on the rearwardly extending handles, these rear supports are lifted off the ground, but the at least one front wheel of the wheelbarrow maintains contact with the ground and transitions from sharing the weight of the wheelbarrow (and load) with the rear supports to bearing most or all of its weight. By holding the handles in an elevated position and pushing them forward (or pulling them backward), a user may cause movement of the wheelbarrow over a distance. During movement, with the rear supports lifted off the ground, the at least one front wheel of the wheelbarrow will continue to bear the weight of the wheelbarrow (and its load) as a result of the front wheel(s) rotating and maintaining contact with the ground over the distance.
One of the main limitations of the classic wheelbarrow is the ability to move heavy loads especially on a hill or incline. Even a physically strong user is limited in the amount of weight they are able to balance, turn and push/pull over a distance with a standard wheelbarrow carrying a heavy load. This difficulty is even greater when a heavy load is carried (i.e., pushed/pulled) uphill against gravity. Indeed, a user may be able to move a load in a wheelbarrow over level ground but not be able to transport the same load uphill due to the added effects of gravity.
The placement of a motor on the underside of a wheelbarrow to assist in moving heavy loads by use of a drive chain engaged with the motor and a sprocket on the front wheel axle of the wheelbarrow has been described. However, these prior designs have a number of drawbacks. The use of a drive chain connected to a sprocket on a front wheel axle makes it difficult to reversibly engage/disengage the drive motor and drive chain from the front wheel axle of the wheelbarrow during use. Furthermore, many prior motorized wheelbarrow designs require the motor and/or drive chain to be positioned off to one side of a front-to-back center plane of the wheelbarrow, which may contribute to a weight imbalance for the user that may make the wheelbarrow difficult to control and maneuver, especially when emptying a load. This off-center (weight-imbalanced) placement of the motor and/or drive chain may be due to the motor and/or drive chain being in a side mounted arrangement or due to interference of a single front wheel that must be positioned within the front-to-back center plane of the wheelbarrow to maintain the side-to-side symmetry and weight balance of the wheelbarrow. A wheelbarrow having a balanced and symmetrical weight distribution is easier to maneuver and control during all aspects of its use, such as when transporting a load, dumping or emptying a load, etc. As a result, the drive chain and sprocket on the front wheel axle used with these prior designs (to impart rotation to the front wheel axle) must be positioned off to one side of this center plane of the wheelbarrow to access the front wheel axle sprocket that must be positioned off to one side of the centered front wheel. Yet another limitation with these prior designs is that a longer drive chain is needed to reach from the drive motor to the front wheel axle, which adds extra weight to the wheelbarrow that may further contribute to any weight imbalance. Having the drive chain mounted on the front wheel axle also raises safety issues for the user.
Therefore, what is needed in the art is an improved system, apparatus and method for facilitating the movement of a wheelbarrow and its load over a distance that is (i) relatively lightweight, (ii) “center-able” in general alignment with a single front wheel and the front-to-back center plane of the wheelbarrow to maintain its symmetry and weight balance, and/or (iii) easily and reversibly engaged/disengaged from the front wheel by a user during use.